CN112433369A

CN112433369A - Head-up display for vehicle

Info

Publication number: CN112433369A
Application number: CN202010854117.1A
Authority: CN
Inventors: S·默尔贝尔; C·迪贾诺维奇; M·里希特
Original assignee: Audi AG
Current assignee: Audi AG
Priority date: 2019-08-26
Filing date: 2020-08-24
Publication date: 2021-03-02
Anticipated expiration: 2040-08-24
Also published as: CN112433369B; US11440410B2; US20210061103A1; DE102019122780B3

Abstract

The invention relates to a method for operating a head-up display (HUD) of a vehicle, in which a control unit of the vehicle converts a display image to be displayed by means of a windshield of the vehicle into a reflection image to be reflected by the windshield, and a display unit of the head-up display of the vehicle assigned to the windshield displays the converted reflection image; the invention also relates to a controller for a head-up display of a vehicle and to a vehicle.

Description

Head-up display for vehicle

Technical Field

The invention relates to a method for operating a Head-Up Display (HUD) of a vehicle, in which a control unit of the vehicle converts a Display image that can be displayed by means of a windshield of the vehicle into a reflection image that is to be reflected by the windshield, and a Display unit of the Head-Up Display of the vehicle assigned to the windshield displays the converted reflection image. The invention also relates to a controller for a head-up display of a vehicle and to a vehicle.

Background

The head-up display is used to display information about the vehicle or the driving condition of the vehicle to the driver of the vehicle. The driver can visually perceive the information displayed by the head-up display during driving of the vehicle and at the same time can be aware of the traffic situation in front of the vehicle. The information is thus displayed to the driver in the driver's normal field of view by means of the head-up display, i.e. the driver does not have to look away from the traffic situation in order to visually perceive the displayed information.

To this end, a head-up display includes: a windshield of a vehicle, which serves as a reflection surface; and a display unit assigned to the windshield, which displays a reflected image to be reflected by the windshield. In general, the head-up display also has an optical assembly which is arranged in the light path of the head-up display between the display unit and the windscreen and comprises at least one lens and/or mirror. The optical assembly is configured to optimize and/or steer the reflected image displayed by the display unit onto an inner face of the windshield. The optical assembly allows great flexibility in positioning and orienting the display unit relative to the windshield.

Windshields for vehicles typically have a non-constant curvature that generally causes bowing of the windshield. In the assembled state, the windshield is curved outward, i.e., the outer surface of the windshield is curved convexly, while the inner surface of the windshield is curved concavely.

The controller is therefore configured to convert a display image to be displayed by the head-up display, which display image is provided for reflection by the flat reflection surface, into a reflection image to be reflected by the curved windscreen, so that the driver does not perceive a distortion of the displayed display image despite the bending of the windscreen. For this purpose, the transformation performed by the control unit must reverse the distortion caused by the windshield in order to obtain a distortion-free display under the interaction of the transformation and the bending.

However, due to manufacturing tolerances, the curvature of nominally identical windshields inevitably fluctuates, which may correspondingly lead to manufacturing-induced distortions of the display.

To solve this problem, document DE 112015001322T 5 discloses a method for configuring a head-up display of a vehicle, in which a transformation is selected from a plurality of transformations by means of a predetermined correction pattern in order to reduce distortion of a display image displayed by means of a windscreen of the vehicle, which is caused by curvature deviations of the windscreen due to manufacturing.

Another aspect to be considered in head-up displays is that the viewing direction of the driver depends on the driving situation of the vehicle. For example, in the case where the vehicle speed is high, the driver's sight line is mainly directed to a distant area in front of the vehicle, and thus the sight line is elevated, whereas in the case of low speed, the driver tends to lower the sight line to observe a close area in front of the vehicle.

Thus, document DE 102015109027 a1 discloses a method for operating a head-up display of a vehicle, in which the vertical position of information displayed by means of a windshield of the vehicle is determined as a function of the driving speed of the vehicle.

However, the curvature of the windshield may vary in the vertical direction, so that a variation in the vertical position of the display causes distortion of the display.

Document DE 102007001266 a1 addresses this problem and discloses a method for operating a head-up display of a vehicle, in which an optical sensor detects an eye position of a driver of the vehicle, which eye position is dependent on the driving speed of the vehicle, and a controller calibrates the head-up display continuously in real time during the driving of the vehicle as a function of the detected eye position.

Many head-up displays are also configured to provide the driver with Augmented Reality (AR), i.e. to highlight, mark, supplement, etc. real objects arranged in the area in front of the vehicle and visible through the windscreen. This presupposes a fixed spatial relationship between the real object and the AR enhancement displayed by the head-up display.

However, during and due to the travel of the vehicle, for example due to wind resistance which varies with the travel speed, the windshield is dynamically deformed, thereby also causing an undesirable distortion of the display of the head-up display. Such dynamic distortion changes, inter alia, the spatial relationship between the real object and the AR-enhancement and is particularly annoying to the driver, since the driver perceives different spatial relationships between the real object and the AR-enhancement at different driving speeds.

Disclosure of Invention

The object of the present invention is therefore to provide an improved operating method for a head-up display of a vehicle, which enables an at least approximately distortion-free display independently of the driving speed of the vehicle. Furthermore, it is an object of the invention to provide a controller for a head-up display of a vehicle and a vehicle.

The invention relates to a method for operating a head-up display (HUD) of a vehicle, in which method,

-a controller of the vehicle converts a display image to be displayed by means of a windscreen of the vehicle into a reflection image to be reflected by the windscreen; and is

The display unit of the head-up display assigned to the windscreen displays the converted reflection image.

The invention can be used for any head-up display of a vehicle, whereby a large number of application possibilities are obtained.

According to the present invention, the controller determines the warp matrix/deformation matrix according to the driving speed value of the vehicle in order to convert the display image. Warping is understood as a technique that can compensate for two-dimensional distortions of two-dimensional images, for example the so-called pincushion effect (Kisseneffekt). In the case of head-up displays, the distortion to be compensated for in the case of warping is caused by the curvature of the windshield. The warp matrix used for the transformation is a function of the speed of travel in order to take into account the dependence of curvature on speed. In this way, the transformation of the display image can be individually adjusted to each driving speed.

In a preferred embodiment, determining the warp matrix as a function of the speed comprises using two or more constant warp matrices, each assigned to a predetermined driving speed value different from one another. The constant warp matrix may cover a range of the travel speed of the vehicle and is selected by the controller in dependence on the current travel speed of the vehicle, that is, different constant warp matrices are used in sequence during travel of the vehicle.

Advantageously, determining the warp matrix from the speed comprises using one constant warp matrix assigned to a value of zero for the travel speed and at least one constant warp matrix assigned to a value of non-zero for the travel speed. The constant warp matrix assigned to the zero value enables distortion-free display during standstill of the vehicle, for example in front of a red light or during traffic congestion. At least one constant warp matrix assigned to the non-zero values is used to reduce dynamic distortion. The plurality of constant warp matrices assigned to respective non-zero values may better overcome dynamic distortion of the display over a range of travel speeds.

Preferably, for a value of the travel speed different from any of the predetermined travel speed values, determining the warp matrix from the speed comprises interpolating from the travel speed values based on at least one constant warp matrix assigned to the predetermined travel speed value. For values of the driving speed between the predetermined values, the distortion of the display can be further reduced by means of interpolation. Further, display jitter is prevented when the switching constant warps the matrix.

In another embodiment, the controller receives the driving speed value indirectly or directly from a sensor of the vehicle. The controller can, for example, obtain a current driving speed value transmitted by another controller of the vehicle, for example a navigator.

The subject matter of the invention also includes a controller for a head-up display of a vehicle, which is configured to convert a display image to be displayed by means of a windscreen of the vehicle into a reflected image to be reflected by the windscreen. Each head-up display of a vehicle includes such a controller, so that the present invention may find many applications. The controller can be integrated into the display unit of the head-up display or into the infotainment system of the vehicle.

According to the present invention, the controller is configured to determine the warp matrix according to a traveling velocity value of the vehicle in order to convert the display image. Thus, the controller can compensate for dynamic deformation of the windshield, for example, due to wind resistance during travel of the vehicle. If the controller integrated into the infotainment system of the vehicle cannot be configured in this way, the head-up display can still be retrofitted within the meaning of the invention without modifying the infotainment system by integrating the controller into the display unit of the head-up display.

In an advantageous embodiment, the controller comprises one constant warp matrix assigned to a value of zero of the travel speed of the vehicle and at least one constant warp matrix assigned to a predetermined non-zero travel speed value. The constant warp matrix may be stored in a local memory of the controller. If the vehicle is stationary, the controller uses the constant warp matrix assigned to zero values for the conversion, while using the other constant warp matrix during vehicle travel.

In a preferred embodiment, the controller comprises an interpolation module configured to interpolate from the values of the travel speed for values of the travel speed different from any predetermined value based on at least one constant warp matrix assigned to the predetermined value. The interpolation module calculates a warp matrix for values of travel speed that lie between predetermined values. The interpolation module is advantageously implemented as software, by means of which the method according to the invention can be subsequently equipped with an existing controller.

In other embodiments, the controller includes an interface configured to receive a value of a travel speed of the vehicle. The interface may be, for example, a standardized interface for a bus system of a vehicle.

The subject matter of the invention furthermore includes a vehicle having a windshield, a display unit assigned to the windshield, a sensor providing a driving speed value of the vehicle, and having a controller according to the invention, which is connected directly or indirectly to the display unit and the sensor. The vehicle therefore comprises a head-up display which enables an at least approximately distortion-free display despite the dynamic deformation of the windshield during driving of the vehicle. The controller can be connected, for example, via the bus system of the vehicle, to other controllers of the vehicle, for example to an ESP controller with wheel speed sensors or to a navigator with a GPS sensor, or indirectly to the sensors.

The head-up display is particularly suitable for displaying augmented reality, since it ensures that the fixed spatial relationship between the real object and the augmented reality, which is arranged in the region in front of the vehicle and is visible through the windshield, is independent of the driving speed.

A significant advantage of the operating method according to the invention for a head-up display of a vehicle is that distortions of the display of the head-up display due to dynamic deformations of the windshield are at least almost avoided. Especially in the presence of display enhancement, the driver is not disturbed by an unstable spatial relationship between the real object and the AR enhancement. Furthermore, it is advantageous if an existing head-up display can be retrofitted for the operating method.

Drawings

The invention is illustrated schematically by means of embodiments in the drawings and will be further explained with reference to the drawings. Wherein:

fig. 1 shows a vehicle according to an embodiment of the invention in a schematic view;

fig. 2 shows a partial block diagram of a controller according to an embodiment of the invention in a schematic view.

Detailed Description

Fig. 1 shows a vehicle 10 according to an embodiment of the invention in a schematic view. The vehicle 10 includes: an ESP controller 15 having a sensor 13 designed as a wheel speed sensor for providing a driving speed value 25 (see fig. 2) of the vehicle 10; and a head-up display having a windscreen 11, a display unit 12 assigned to the windscreen 11, a mirror 14 assigned to the display unit 12 and a controller 20 connected to the display unit 12 and the sensor 13. The controller 20 and the sensor 13 are connected indirectly via the ESP controller 15, but may alternatively also be connected to the sensor via another controller of the vehicle 10, for example a navigator, or also directly to another sensor of the vehicle.

Fig. 2 shows a partial block diagram of the controller 20 according to an embodiment of the invention in a schematic view. The controller 20 is adapted for use with a heads-up display of the vehicle 10 and includes an interface 22. The interface 22 is configured to receive a driving speed value 25 of the vehicle 10.

Further, the controller 20 includes a constant warp matrix 23 assigned for a zero value of the running speed of the vehicle 10 and a constant warp matrix 24 assigned for a non-zero predetermined running speed value. It is clear that the controller 20 may comprise further constant warp matrices which are assigned to further non-zero and respectively different predetermined driving speed values.

The controller 20 also includes an interpolation module 21. The interpolation module 21 is configured to interpolate a warp matrix 26 for the received driving speed value 25 that differs from any predetermined value on the basis of at least one of the two

warp matrices

23, 24 and from the received driving speed value 25.

By means of the above-described components, the controller 20 is configured to convert a display image 27 to be displayed by means of the windshield 11 of the vehicle 10 into a reflection image 28 to be reflected onto the windshield 11, and to convert the display image 27, to determine the warp matrix 26 from the received driving speed value 25 of the vehicle 10.

During operation of the vehicle, i.e., driving, the head-up display is continuously operated in real time as follows. The controller 20 receives the current driving speed value 25 of the vehicle 10 from the sensor 13 and determines a warp matrix 26 from the received driving speed value 25 in order to convert the display image 27. For this purpose, the interpolation module 21 uses two

constant warp matrices

23, 24 and, if necessary, also other constant warp matrices.

If the received driving speed value 25 differs from any of the predetermined driving speed values, the interpolation module 21 interpolates a warp matrix 26 on the basis of at least one of the two

constant warp matrices

23, 24, ideally on the basis of the two

constant warp matrices

23, 24 and possibly further constant warp matrices, and on the basis of the received driving speed value 25. Otherwise, the interpolation module 21 uses the

constant warp matrices

23, 24 assigned to the received values 25 directly as warp matrices 26 without interpolation.

By means of the determined warp matrix 26, the controller 20 converts a display image 27 to be displayed by means of the windscreen 11 of the vehicle 10 into a reflection image 28 to be reflected by the windscreen 11. In a further step, the display unit 12 displays the converted reflection image 28, which is perceived by the driver of the vehicle 10 as a distortion-free display image 27 on the windscreen 11 at any driving speed of the vehicle 10.

List of reference numerals

10 vehicle

11 wind screen glass

12 display unit

13 sensor

14 mirror

15 ESP controller

20 controller

21 interpolation module

22 interface

23 constant warp matrix

24 constant warp matrix

25 running speed value

26 warp matrix

27 display image

28 reflection image

Claims

1. A method for operating a head-up display of a vehicle (10), in which,

-a controller (20) of the vehicle (10) converting a display image (27) to be displayed by means of a windscreen (11) of the vehicle (10) into a reflection image (28) to be reflected by the windscreen (11);

-a display unit (12) of a head-up display of the vehicle assigned to the windscreen (11) displays the converted reflected image (28);

-the controller (20) determines a warp matrix (26) from the driving speed values (25) of the vehicle (10) for converting the display image (27).

2. A method according to claim 1, characterized in that determining a warp matrix (26) from the speed comprises using two or more constant warp matrices (23) assigned for predetermined driving speed values different from each other.

3. A method according to claim 1 or 2, characterised in that determining a warp matrix (26) from the speed comprises using one constant warp matrix (23) assigned for zero values of the travelling speed and at least one constant warp matrix (24) assigned for non-zero predetermined travelling speed values.

4. A method according to claim 2 or 3, characterised in that for a driving speed value (25) different from any predetermined driving speed value, determining a warp matrix (26) from the speed comprises interpolating from the driving speed values (25) based on at least one constant warp matrix (23, 24) assigned to the predetermined driving speed value.

5. Method according to any of claims 1 to 4, characterized in that the controller (20) receives the driving speed value (25) indirectly or directly from a sensor (13) of the vehicle (10).

6. A controller (20) for a head-up display of a vehicle (10) is configured to convert a display image (27) to be displayed by means of a windscreen (11) of the vehicle (10) into a reflection image (28) to be reflected by the windscreen (11), and to determine a warp matrix (26) from a driving speed value (25) of the vehicle (10) for converting the display image (27).

7. A controller according to claim 6, characterised in that the controller comprises one constant warp matrix (23) assigned for zero values of the running speed of the vehicle (10) and at least one constant warp matrix (24) assigned for non-zero predetermined running speed values.

8. A controller according to claim 7, characterised by having an interpolation module (21) configured to interpolate a warp matrix (26) from the driving speed values (25) based on at least one constant warp matrix (23, 24) assigned to predetermined values for driving speed values (25) different from any predetermined value.

9. A controller according to any one of claims 6 to 8, characterised in that the controller has an interface (22) configured to receive a value (25) of the speed of travel of the vehicle (10).

10. Vehicle (10) with a windscreen (11), a display unit (12) of a head-up display assigned to the windscreen (11), a sensor (13) providing a driving speed value of the vehicle (10) and a controller (20) according to any one of claims 6 to 9, which is directly or indirectly connected with the display unit (12) and the sensor (13).